PetriKey

Bacterium

Clostridioides difficile

Spore-forming anaerobic rod

klos-TRID-ee-OY-deez dih-FIH-sil

Gram positivegram-positiverodanaerobesporetoxin

High-yield clue

Spore-forming anaerobe + toxin + antibiotic-associated colitis vocabulary.

Overview

A spore-forming anaerobic rod used to teach toxin-mediated colitis vocabulary and disruption of normal flora concepts.

Classification

  • Gram-positive
  • Rod
  • Anaerobe
  • Spore-former

Lab & identification clues

  • Toxin testing vocabulary
  • Spore-forming rod
  • Anaerobic growth concept

Associations

  • Pseudomembranous colitis vocabulary
  • Normal flora disruption
  • Infection-control concepts

Commonly confused with

  • Clostridium perfringens
  • Bacillus species

Your notes

Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.

OpenStax: Microbiology 2e organism classification foundationssourceNCBI Bookshelf: Medical Microbiology organism chapterssourceCDC: CDC disease and public-health topic pagessource